How do you discover a need that nobody yet knows about? This is where the product breakthroughs come through.

The designer has an obligation to provide an appropriate conceptual model for the way that the device works. It doesn't have to completely accurate but it has to be sufficiently accurate that it will help in both the learning of the operation and also dealing with novel situations.

The hardest part of design ... is keeping features out.

Products were once designed for the functions they performed. But when all companies can make products that perform their functions equally well, the distinctive advantage goes to those who provide pleasure and enjoyment while maintaining the power. If functions are equated with cognition, pleasure is equated with emotion; today we want products that appeal to both cognition and emotion.

Forget the complaints against complexity; instead, complain about confusion.

What makes something simple or complex? It's not the number of dials or controls or how many features it has: It is whether the person using the device has a good conceptual model of how it operates.

Any time you see signs or labels added to a device, it is an indication of bad design: a simple lock should not require instructions.